Oil-burning system



June 24, 1930. J. w. CANNON 1,766,242

OILVBURNING SYSTEM Filed Jan. 28, 1925 4 Sheets-Sheet 2 Jung 24, 1930. J w, CANNQN 1,766,242

OIL BURNING SYSTEM Filed Jan. 28, 1925 4 Sheets-Sheet s mew June 24, 1930. w, CANNON 1,766,242

OIL BURNING SYSTEM Fileq Jan. 28, 19 25 4 sheets sheet 4 '0 i l M nip 3 Patented June 24, 1930 airs!) STATES JOHN W. GANNON, 0F PROVIDENCE, RHODE ISLAND OIL-BURNING SYSTEM Application filed January 28, 1925. Serial No. 5,218.

ner which will result in the complete combustion of the fuel and with the maximum utilization of the heat units developed thereby; which will be safe in operation; which can be operated, without interruption, under a widely varying rate of fuel consumption; which can be operated continuously and extensively without the clogging of the system or the building up of undue pressures therein; and also which can burn completely and safely, and utilize efficiently, within a given space a greater quantity of such fuel per hour than any other apparatus or system of similar capacity with which I am familiar.

I accomplish the foregoing and other obj ects, which will appear hereinafter through the construction and arrangement of parts shown in the drawings, wherein Fig. 1 represents an elevation, with certain parts broken away, of a system or apparatus embody ing my invention; Fig. 2 a detail in central vertical section through the combustion chamber of my apparatus or system; Fig. 3 a detail in central longitudinal section through the liquid fuel ejector; Fig. 4 a plan view and Fig. 5 a sectional side elevation of a float tank employed in the apparatus shown in Fig. 1; Fig. 6 a sectional View corresponding to the line 66 of Fig. 5; and Fig. 7 a sectional end elevation of such tank.

As oil is the liquid fuel commonly used for the purposes, for which my system is designed, such term will be employed hereinafter, but without any intention of limiting my invention to any special liquid fuel.

The particular embodiment of my invention shown herein is one which is desi ned for use in a domestic heater, such as is employed for house-heating purposes and where it is impossible and inconvenient to supply oil to the burner from a tank buried or otherwise located below the level of the burner or ejector (to be described hereinaf er). in house-heating installations, it is preferable that the fuel oil tank should be located outside the building at a depth which will bring the top of the tank below the ejector. However, as it is often inconvenient and sometimes impracticable to locate the tank in this manner I have shown in the drawings and will explain hereinafter the manner in which the advantages of my system may be realized where the preferred tank arrangement cannot be employed.

My system or apparatus comprises gener ally means including atank for supplying water under a predetermined pressure through a superheating flash coil to an ejector; a tank or other source of supply for oil leading to said ejector, but with means for maintaining the level of such oil below the ejector except when the ejector is in operation; a burner receiving a mixture of superheated steam and atomized oil delivered from the ejector and preferably superheated in transit to the burner and a combustion chamber, preferably composed principally of silicon carbide, into which the burner discharges and which is interposed between the burner nozzle and the flash or' 'superheater coil. The apparatus or system will now be described in detail in connection with the drawings, and the advantages which arise from the construction and arrangement of the various parts of the same will be pointed out in con.- nection with such description.

Describing the parts by reference characters,A indicates a furnace'of a type employed for domestic heating and having a water jacket A and a dome A from which steam or vapor may be delivered to the point or points of use. The dome is provided with the usual pressure-diaphragm cell A which is operatively connected with a lever A pivotally supported at A and provided with the usual weight A at the rear of said pivot, the front of the leverbeing connected, by means to be described hereinafter. with the valve which controls the flow of water to the ejector.

Supported upon the top B of a base B in said furnaceis a combustion chamber. This combustion chamber comprises an inner cylindrical member of refractory material, preferably silicon carbide, and preferably made up of a plurality of sections C, C, the

ii a

bottom section being seated upon the top B and having in the bottom thereof an annular slab (also preferably of silicon carbide) having a central opening C from the bottom of which depends a frusto-conical bell C adapted to admit air to support the combustion of the combustible mixture supplied to the said cylinder.

Surrounding the upper portion or section of the cylinder G, C, is an outer cylindrical member D of refractory material, preferably silicon carbide, the upper end of the cylinder D extending above the upper end of the section C and being closed by a suitable cap or cover D. The lower end of the cylinder D is supported from the top of a lower refractory cylinder surrounding the lower section C of the inner cylinder.- The lower section comprises an outer shell E with a lining E of refractory material, composed preferably of sections of fire brick or similar material, the lining forming a narrow annular space F surrounding the 'lower portion or section C of the inner cylinder. The bottom of the cylinder D is provided with slots D for the escape of the products of combustion into the space surrounding the combustion chamber. The bottom of the annular space F is enlarged outwardly, as shown at F and a burner G is located in such space, the said burner having orifices G in the top thereof and being supplied with gas by means of a pipe G and a valve G (see Fig. 1).

The oil burner, which will be described at length hereinafter, is supplied with a mixture of superheated steam and oil from an ejector, indicated generally at H and shown as located within the shell of the furnace A. near the top of the shell E.

I will now describe the manner in which steam and oil are supplied to said ejector and from the latter to the burner.

1 denotes a pipe by means of which water is forced under pressure (as by a pump) into a pressure tank I, the said pipe being provided with an ordinary globe valve 2 and check valve 3 on the pump-side of the tank. From the tank I, the pipe 4 extends to the ejector, the said pipe being provided with a pressureregulating valve 5 and a gage 6, the valve ensuring the delivery of water at a predetermined pressure from the tank. 5 denotes a manually operated valve which enables the supply from the tank to be cut off. The pipe t is shown as extending to the front of the furnace A, where it is provided with a valve 7 having an operating lever 8. From this valve. the pipe extends upwardly into the bottom of the annular space F, where it is formed into a flash coil K, said coil extending upwardly nearly to the top of the space F From the top of the coil, the pipe 4 extends to and is connected with the T 9 at one end of the ejector H. From this T, a tube 10 extends to a gage 11.

Threaded into the forward end of the T 9 is a nipple 9 The front end of this nipple is provided with a shoulder 12 and has a beveled front portion 13 adapted to abut against the correspondingly beveled rear portion 15 of a T 14. The rear end of this T is also provided with an annular internal seat 16, in front of the beveled portion 15, for the reception of a shoulder 17 the rear end of the ejector nozzle 17. The nipple 9 is con nected to the rear end of the T 14 by means of the shouldered nut 18. Below and surrounding the front of the ejector 17 is a chamber 19, the said chamber being adapted to receive oil from a pipe 20 which is threaded into the said T. The front of the nozzle 17 is arranged in close proximity to a Venturi passage 21 in the front of the T 14, which Venturi passage discharges into a tube 22, threaded into the front end of said T and extending through the part E of the combustion chamber and downwardly through the space F, being bent upwardly into the bell C axially thereof, and provided at its end with a burner nozzle 23. Above the nozzle 23, in the lower combustion-chamber section C, are arranged bafiies such as C for the purpose of facilitating the mixing and combustion of the fuel ingredients delivered from said nozzle and for holding the fire within the lower portion of the chamber. If desired, a pilot burner, indicated at K, may be arranged in operative relation to the nozzle 23, the said burner being connected to the pipe G, as by means of a pipe K having a valve K therein.

As stated hereinbefore, it is preferable to supply the oil to the ejector H from a tank having its top buried or otherwise located below the said ejector. However, when such arrangement is not possible or convenient, I employ the installation shown in the drawings, wherein a local storage tank L is employed, being located within the basement or other compartment containing the furnace A, the said tank being provided with a filling pipe L leading from an outside tank or other 1' source of supply and being provided with a venting pipe L leading to the outside of the building. From the tank L, a pipe L provided with an ordinary globe valve L leads to a float tank M, which float tank is arranged. so as to maintainthe oil at a predetermined inactive level below the ejector H.

The operation of the float tank will beexplained in connection with Figs. 4*? inclusive. wherein the pipe L is shown as communicating with a chamber M adjacent to the bottom of the tank, the said chamber being provided with valve seat M threaded into and extending upwardly from the top thereof. Cooperating with said chamber is a valve 24: mounted on the lower end of a rod 25 the upper end of which is fastened to a rack. This rack comprises a pair of side members N having upturned ends N, one end of the rack being connected to the upper end of the rod 25 by means of a cross member N carrying a yoke N which is adapted to engage pins 26, 26 carried by said rod.

The members N of the rack are connected by cross bolts N and the rack is pivoted intermediate of its ends upon a cross rod 27 supported atits ends on seats 27- carried by the side walls of the tank M.

A float 28 is arranged to operate the rack, the said float having a stem 28 pivotally mounted upon the cross rod 27 through a sleeve 29, the stem being extended beyond said cross rod so as to engage a cross rod 30 carried by and extended betweenthe members N of the rack at one side of the cross rod 27. The body of the stem 28 engages a cross bolt N on the opposite side of the rod 29 from the rod 30.

The rack members N support a ball 31 which, when the rack is inclined in one direction or the other, due to the movement of the float 28 through slight changes of level in the oil in the tank M, will strike one end or the other of the rack, thereby disengaging the valve from its seat or quickly seating the same, according to the direction in which the rack is rocked by the float. This arrangement insures quick and positive opening and closing of the valve 24:, without liability of accumulation of dirt or sediment between the valve and its seat.

At one end of the tank M is located a chamber O, formed between an end wall of the tank and a partition 0' parallel thereto. Should the float and the parts connected therewith fail to close the valve 2d completely, causing the oil to rise above the proper level, then such surplus oil will flowinto the chamber 0 through a pipe O and drop into a trip bucket O shaft G which is supported by the partition 0' and the adjacent wall of the tank M, the

outer end of the shaft being provided with an connected by a chain with arm 32 which the handle 34 of a valve 34 in the pipe L The trip bucket is of such shape that, when approximately filled with oil overflowing througl'i the pipe 0 it will drop in the manner indicated in dotted lines in Fig.

such position by means of a'weight 35 carried by an arm 35 which is secured to the shaft 0*. L The construction and arrangement of the tanks L and M and the parts cooperating therewith ensure the maintenance of thedesired oil level below the ejector H.

Reference has been made hereinbefore to the valve '7 and the operating handle 8 therefor. This handle or lever is shown as projecting into a coupling member 36 whereby it This bucket is secured to a.

7, beinc: assisted in such movement and retained in is connected to a rod 37 having its upper end attached to the front end of the lever A and its lower end connected with the piston 38 of a dash pct 39. The dash pot is so arranged that the piston cell A contracts, for the purposes of preventing toorapid a supply of water to the coil K, as such rapid supply would result in fluctuations in the fire. he dash pot enables the valve 7 to be operated quickly and direct ly as the cell A is expanded by the pressure of the steam generated in the furnace.

' With the parts constructed and arranged as described, in placing the system in operation the gas burner G will be lighted and the coil K will be heated for a time sufficient to secure the flashing into steam of the water to be admitted therethroughsay five minutes. At the end of this period, the operator will open the valve 5, thereby enabling the water to pass through the valve 7 to the coil K, where it is superheated and passes under high velocity and pressure to the ejector H. Due to the action of the ejector, the oil is drawn up from its inactive level below said ejector, is atomized by the superheated steam, and the mixture is delivered through the pipe 22 to the nozzle 23, being superheated in its through said pipe; the coil K is such flashed into steam therein, it is delivered at an extremely high velocity into the ejector where, in passing across the chamber 19 and through the Venturi passage 21, it produces a sufficient partialvacuum to lift the oil in the pipe 20 into the chamber, enabling the steam jet to atomize the oil and deliver it into the pipe 22, where it is further atomized and commingled With the steam, the mixture being superheated and cracked into a gas in the pipe 22 before its delivery through the nozzle 23. During vthe starting operation, some of the steam will be delivered through the pipe 22 to the nozzle 23 before the oilcan be, lifted into the chamber 19. This will result in instituting an induced draft in the combustion chamber in advance of the supply of the gaseous mixture t-hereto, thus eliminating the possibility of a flash back when the mixture is ignited. The air necessary to support the combustion is entrained through the bell C The baffles C serve to break up the jet of gaseous fuel delivered through the nozzle 23, facilitates its admixture with the air supplied through the bell C and maintains the fire within the lower portion of the combustion chamber. This mixture, being ignited, as by the pilot burner, burns within the combustion chamber formed'by the sections C, C and D, the gaseous products being discharged through the slots D in operative relation to the surrounding water jacket A.

As prev ously stated, the inner combustion cylinder C, C is composed preferably of silipassage The internal dlameter of 38 will descend slowly as the that, whentlie water is same-although,

con carbide which, because of its extreme permeability to heat and its high heat-radiating qualities, shortly becomes heated to incandescence throughout its length, the section C heating the coil In: by radiation, it being understood that the burner G will be extinguished after the preliminary or starting operation. The coil and the portion 22 of the pipe 22 are not exposed to direct contact with the products of combustion; hence these parts are capable of use for an indefinitely prolonged period of time without oxidation. The parts D and 1) also become heated in like manner by the fire therewithin and, being arranged in proper operative rela tion to the water jacket A and the dome A will serve to heat these parts by radiation, without any localization of the heat. The gaseous mixture discharged into the combustion chamber will have been completely consumed during its passage therethrough, which will result, not only in heating the water jacket and the dome in a most eilicient manner, but will prevent the said jacket and dome from being injured by the products discharged from the said chamber.

Reference has been made hereinbefore to the pressure and high velocity of the steam flowing through the flash coil. This pressure and velocity will vary in accordance with the particular installation. F or a domestic heatingplant, good results have been 01 tained by using a coil and superheater having each a bore of 14 th inch, together with an ejector nozzle having a minimum diameter of 30/1000th inch, a Venturi passage having a minimum diameter of 54/1000th inch; and a burner nozzle having a bore of 3/32nd inch. Employing this ratio of orifice-dian'reter adapts the system for use with a wide range of oil consumption-for instance, from one 'quart per hour to three gallons per hour, and Without any interruption of the continuous operation of the heater.

In practice, the water will be supplied under a relatively high but constant pressure to the valve 7-say from to 40 pounds per square inchthis pressure being suitable for the burner-nozzle and ejector-nozzle capacity herein set forth. Except when operating, the oil level will be maintained at from eighteen inchesto two feet below the eector, and preferably not more than five feet below the inslarge or industrial heat ing. it is possible to operate with an inactive oil level at from ten to twentyfeet below the ejector, in which ,case the oil consumption must he ate more uniform rate than is possiblewhere the inactive oil level is closer to the ejector.

lVith the water pressure mentioned and the inner diameter or bore of the coil and superheater as given, the steam will leave theejector nozzle at a speed of about 240,000 feet per minute and under a pressure of 35 to 40 pounds per square inch. of the steam insures not only the etlicient operation of the ejector in elevating the oil thereinto, but the complete atomization of the oil and the complete admixture of such oil and steam and the cracking of the mixture in its passage to the burner nozzle. Furthermore, the high velocity of the steam through the coil K and of the steam-and-oil mixture through the superheater pipe 22 will main tain the interior of these ducts in a clean and polished condition, effectually preventing the accumulation of any of the solid constituents of the oil within the superheater. Should any of the carbon and other solid constituents of the oil fail to be cracked within the duct 22, 22 such constituents will be carried along by the gaseous mixture and delivered into the combustion chamber, where they will be completely consumed.

It should be noted that, in the ordinary operation of my system, the only control valve employed is in the water supply, the said valve being indicated at 7 and being operated, in the installation shown herein, by the diaphragm cell A It will be obvious that the valve may be controlled by a thermostatic connect-ion, in the same manner that gas and oil valves for heating furnaces are operated. lVhether the valve be operated by the usual thermostat or by the diaphragm cell, the volume of the fire and the resultant volume and temperature of steam or other heatingfiuid generated in the furnace will be dependent upon the amount of water passing through the valve 7 to the coil K and burner nozzle 23. With an installation such as shown and described herein, the system will operate with an effective pressure of as low as 20 pounds per square inch of water delivered to the coil K; and the steam generated from such coil will lift the oil into the ejector H, serving to maintain a low fire in the combustion chamber. Under these conditions, the consumption of oil will be about one quart per hour and the burner and the combustion chamber will develop sufficient heat to evolve enough superheated steam to operate the ejector and keep the walls of the combustion chamber hot. lVhen the valve 7 is fully opened and the Water is supplied to the coil at the maximum predetermined pressure (say 35 to 40 pounds per square inch) the system will consume about 3 gallons of oil per hour; and, notwithstanding this wide range in fuel consumption, the ejector will operate to produce a proper admixture of oil and superheated steam for the corresponding different sizes of fires, and the advantages hereinbefore pointed out will be realized throughout all these ranges of operation.

Because of the nature of the control, it will be obvious that the chances for fire or explosion are reduced to a minimum. There can be no flow of oil to the combustion chamber un- This extreme speed less the burner is operating and generating steam in the coil'K; as soon as the steam ceases to flow through said coil, or to flow at a velocity which will operate the ejector, the sup ply of oil to the combustion chamber automatically ceases and the fire is extinguished. Furthermore, as there are no valves for the flash coil and the latter is kept free from clogging by the high velocity of the steam passing therethrough, there is no danger of rupturing the said coil; and, as the control valve is in the water supply line instead of in the steam line, danger of clogging the valve, when slightly opened for minimum fire conditio'ns, is eliminated.

The ejector acts as a safety device in the event that, for some unforseen reason, the pressure of the steam supplied thereto should become dangerously high. With the dimensions of orifice-diameters given hereinbefore, should steam be generated at a greater rate than is consistent with safety, it will be unable to pass freely through the Venturi passage. This will result in creating a back pressure in the chamber 19 and reducing the ejector action of the steam upon the oil, with a corresponding reduction in the oil supply to the said chamber, and the tire will be automatically reduced or even extinguished, depending upon the degree of super-normal pressure in the steam.

By using silicon carbide for the combustion chamber, the gaseous mixture from the burner will be consumed without the development of any disagreeable odors. Furthermore, by reason of the use of this materlal and the construction of the combustion chamber, 1 am enabled to muiile the noise made by blowing the gaseous mixture from the nozzle 23 as well as the noise produced by the heat waves within said chamber.

By using for the steam generator a flash coil of relatively small bore, only. a small quantity of steam is being generated at any given amount of operation, and this steam is used as quickly as it is generated. This means that the burner may be put into and out of operation with a minimum loss of time, insuring positiveness and sensitiveness of control. This construction also prevents fluctuations of the pressure in the steam which operates the ejector, insuring a steady fire. a

Furthermore, in the operation of my in vention, combustion is completed within the combustion chamber, producing a very high temperature therein and a corresponding high temperature in the outer surfaces of the walls D and D of said chamber. This results in a very efii-cient heating of the acket A, but without any liability o'f'damage or injury to the walls thereof, due to the fact that the said walls are exposed only to the radiant heat from the combustion chamber and to the heat of the products of combustion deliyered through the slots D but which products are themselves at a relatively low temperature, due to the fact that the combustion within the chamber is complete.

In the preceding descriptive matter, I have given certain dimensions of ejector parts, superhea-ter, flash coil, and burner-nozzle, these dimensions being particularly suitable for a domestic heater of the type shown herein. here greater capacity is desired,

in industrial heating, a corresponding increase in the size of the foregoing parts and in the pressure of the water supplied to and of the steam generated will follow, together with a like increase in burner and combustion-chamber capacity and in the amount of oil consumed. in all installations, however, the supply of the oil will be proportional to and controlled by the water supply. For instance, should the burner be operating at one-third of the maximum water supply to the coil, approximately one-third of the full steam capacity of the coil will be generated. The steam will feed to the ejector and mix therewith approximately one-third of the maximum oil supply; the burner nozzle will entrain approximately one-third of the maximum amount of air, for supporting the combustion of this mixture; and the combustion will be attended with about one-third of the maximum stack loss.

By increasing the effective length of the coil K, a greater quantity of steam p r unit of time will be generated, with a corresponding increase in pressure of said steam and with a like proportional increase in the amount of oil taken from the ejector by such steam-up to the point referred to hereinbefore when a back pressure of steam will be createdin the ejector which will cut off the supply of'oil thereto.

Where a thermostat control is' employed, either as a substitute for or in addition to the pressure-diaphragm control shown herein, there is a marked saving of efliciency in the operation of my systemover other systems with which I am familiar, due to the fact that, unless there is a material change in the outdoor temperature, the burner will tend to operate at a constant capacity or fire, without fluctuations between minimum and maximum. This results, not only in more uniform heating of the house in which the system is installed, but also in a large reduction of loss due to stack temperature. Such a thermostat control may be readily secured by merely connecting the end of the arm A to the ordinary house thermostat by a chain 40, as indicated on 1.

Having thusdescribed my invention, what Iclaim is 1'. In an oil burning system, the combination of acombustion chamber of refractory heat-radiating material, a burner for said chamber, and means for supplying a com bustible mixture to said burner, the said means comprising a steam-generator located outside the said combustion chamber and arranged to be'heated by radiation therefrom, means for supplying water to said generator, an ejector with which the delivery end of said generator communicates, an oil conduit communicating with said ejector, means for supplying oil continuously to a predetermined level in said conduit below said ejector, and a conduit connecting the said ejector with the said burner and arranged to be heated by radiation from said combustion chamber.

2. In an oil burning system, the combination of a combustion chamber of refractory heatradiating material, a burner for said chamber, and means for supplying a combustible mixture to said burner, the said means comprising a flash coil located outside the said combustion chamber and arranged to be heated by radiation therefrom, means for supplying water to said flash coil, an ejector with which the delivery end of said coil communicates, an oil conduitcommunicating with said ejector, means for supplying oil continuously to a predetermined level in said conduit below said ejector, a conduit connecting the said ejector with the said burner and arranged to be heated by radiation from said combustion chamber, and means for control ling the supply of water to said coil.

3 In an oil burning system, the combination of a combustion chamber of refractory heat-radiating material, a burner for said chamber, and means for supplying a oombustible mixture to said burner, the said means comprising a steam generator located outside the said con'ibustion chamber and arranged to be heated by radiation therefrom, controllable means for supplying water under variable pressures to said generator, an ejector with which the delivery end of said generator communicates, an oil conduit comminiicating with said ejector, means for supplying oil continuously to a predetermined level in said conduit below said ejector, and a conduit connecting the said ejector with the said burner and arranged to be heated by radiation fromsaid combustion chamber.

4. An oil burning system comprising a combustion chamber heat-radiating material, a burner for said chamber, a steam generator disposed around said combustion chamber out of contact therewith and arranged to be heated thereby by radiation therefrom, controll-able means for supplying water under variable pressures to said generator, an

ejector connected to the delivery end of said generator, an oil conduit also connected to said ejector, means for supplymg o 1l con tinuously to a predetermined level 1n sa1d conduit below said ejector, and a conduit eittending from the said eject-or to the said combustion cl amber and communicating with said burner and arranged to be heated by radiation from said combustion chamber.

5. An oil burning system comprising a combustion chamber of refractory heatradiating material, a burner for said chamber, a flash coil disposed around said combustion chamber and arranged to be heated thereby by radiation therefrom, controllable means for supplying water under variable pressure to said coil, an ejector connected to the delivery end of said coil, an oil conduit also connected to said ejector, means for supplying oil continuously to a predetermined level in said conduit below said ejector, and a conduit extending from the said ejector to the said combustion chamber and communicating with said burner.

6. An oil burning system comprising a longitudinally disposed refractory combustion chamber, a burner for said chamber, a flash coil disposed'around said combustion chamber and arranged to be heated thereby by radiation therefrom, controllable means forsupplying water under variable pressure to said coil, an ejector connected to the delivery end of said coil, an oil conduit also connected to said ejector, means for supplying oil continuously to a predetermined level in said conduit below said ejector, a conduit extending from the said ejector to the said combustion chamber and communicating with said burner, the said conduit being arranged to be heated by radiation from the said combustion chamber.

7. An oil burning system comprising a combustion chamber, the said chamber comprising an inner member and an outer member surrounding the delivery end of the inner member and spaced therefrom so as to provide an annular passage between said members for the return travel of combustion gases, there being a second outer member extending about the remaining portion of the inner member and providing an annular space therewith, a burner arranged to discharge into the inlet end of the inner member, a flash coil in the space between the inner member and the second outer member, controllable means for supplying water under variable pressure to said coil, an ejector with which the delivery end of the coil is connected, an oil conduit also connected to said ejector, means for supplying oil continuously to a predetermined level in said conduit. below said ejector, and a conduit extending from the said ejector to the said combustion chamber and communicating with the burner, the said conduit being arranged to be heated by the said combustion chamber.

8. An oil burning system comprising a combustion chamber, the said chamber comprising an inner member and an outer member surrounding the delivery end of the inner member and spaced therefrom so as to provide an annular passage between said members for the return travel of combustion gases, there being a second outer member extending about the remaining portion of the inner member and providing an annular space therewith, a burner arranged to discharge into the inlet end of the inner mem her, a generator in the space between the inner member and the second outer member, controllable means for supplying water under variable pressure to said generator, an ejector with which the delivery end of the coil is connected, an oil conduit also connected to said ejector, means for supplying oil continuously to a predetermined level in said conduit below said ejector, and a conduit extending from the said ejector to the sand combustion chamber and communicating with the burner.

9. In the system set forth in claim 8, a separate source of heat arranged in operative relation to the generator for startlng purposes.

10. In an oil burning system, the combination of a combustion chamber of refractory heat-radiating material, a burner for said chamber, a generator located outside said chamber andarranged to be heated by radiation therefrom, controllable means for supplying water under variable pressure to said generator, an oil conduit, a mixing device connected with said conduit and with the delivery end of said generator, and a conduit for conducting the mixture from sald device to said burner, the parts of the mixing device and the bore of the conduit being arranged so that, when the pressure of steam supplied to said mixing device exceeds a predetermined amount, the supply of oil to said device is automatically suspended.

11. In an oil burning system, the combination of a combustion chamber, a burner for said chamber, a flash generator. arrangedto be heated by said chamber, an ejector with which the delivery end of said generator communicates, a conduit extending from said ejector to said burner and arranged to be superheated by said combustion chamber, an oil conduit communicating with said ejector, means for maintaining an inactive level of oil in said oil conduit below said ejector, a conduit for conducting water to said generator, means for supplying water under a predetermined pressure to the last-mentioned conduit, and a valve in such last-mentioned conduit for controlling the pressure of the water supplied to said generator, the first mentioned conduit being of restricted internal diameter but unobstructed whereby the supply o't oil and steam to the ejector and the supply of the mixture of oil and steam from said ejector to the burner will be con trolled by the valve in the water-supply con duit and the accumulation of solid constituents in the first mentioned conduit will be prevented, and temperature-controlled means for automatically operating the said valve.

12. In an oil burning system, the combina tion of a combustion chamber, a burner for said chamber, a generator arranged to be heated by said chamber, a mixing device With which the delivery end of said generator communicates, a conduit extending from said mixing device to said burner, an oil conduit communicating with said mixing device, a conduit for conducting water to said generator, means for supplying water under a predetermined pressure to the last-mentioned conduit, a valve in such last-mentioned conduit for controlling the pressure of the water supplied to said generator, the said generator and the first-mentioned conduit being unobstructed whereby the supply of oil and steam to the mixing device and the supply of the mixture of oil and steam from said mixing device to the burner will be controlled by the valve in the water-supply conduit, and

temperature-controlled means for automatically operating the said valve, the said means comprising an operating arm for said valve, a member, movable through variations in temperature, to which said arm is connected, and a dash pot connected with the said member, the said dash pot beingv constructed and adapted to move slowly in a direction to permit the opening of the said valve and to move quickly in the reverse direction.

.13. In an oil burning system, the combination of a combustion chamber, a burner ar ranged to discharge into said chamber, a generator arranged to be heated by said chamher, a mixing device with which the delivery end of said generator communicates, a conduit extending from said mixing device to said burner, an oil conduit communicating with said mixing device, means for main taining an inactivelevel of oil in said con duit below said ejector, a conduit for conduct ing water to said generator, means for supplying water under a predetermined pressure into said conduit, a valve in'said conduit for controlling the pressure of the water supplied to said generator, the said generator and the first-mentioned conduit being unobstructed whereby the supply of oil and steam to the mixing device and the supply ofthe mixture of oil and steam from said mixing device to the burner will be controlled by the valve in the water-supply conduit, and means for automatically operating the said valve, the said means comprising anoperating arm for said valve, a member, movable through vvariations in temperatureand pressure, to which said arm is connected, and a dashhpot connected with the said member, the said dash pot being adapted to move'slowly in a direction to permit the opening of the said valve and to move quickly in the reverse direction.

' 14:. In an oil burning system, the combination ofa combustion chamber of refractory heat-radiating material, a burner for said chamber, and means for supplying a combustible mixture to said burner, the said means comprising a flash coil arranged to be heated by radiation from the said chamber, means for supplying water to said coil, an ejector with which the delivery end of the said coil communicates, means for supplying oil to said ejector, and a conduit extending from the ejector to the burner and arranged to be superheated by the said combustion chamber.

15. In an oil burning system, the combination of a combustion chamber of refractory heat-radiating material, a burner for said chamber, and means for supplying a combustible mixture to said burner, the said means comprising a flash coil arranged to be heated by radiation from the said chamber, means for supplying water to said coil, an ejector with which the delivery end of the said coil communicates, an oil conduit communicating with said ejector, means for maintaining an inactive level of oil below said ejector whereby the steam from the coil will operate to lift the oil in said conduit to said ejector and atomize and eject the same therefrom, and a conduit conducting such mixture of oil and steam to the said burner, and arranged to be superheated by radiant heat from said chamber.

16. In an oil-burning system; the combination of a combustion chamber'of refractory heat-radiating material, a burner for said chamber, and means for supplying a combustible mixture to said burner, the said means comprising a flash coil of restricted internal diameter located outside the said chamber and arranged to be heated by radiant heat therefrom, means for supplying water to said coil, a mixing device with which the delivery end of said coil communicates, an oil conduit communicating with said device, and a conduit delivering the mixture of oil and steam from'said device to said burner and arranged to be heated by radiantheat from said chamber, the last-mentioned conduit being also of restricted internal diameter, whereby the steam generated in the coil will be delivered to the mixing device at a high velocity and the mixture from said device will pass through the second conduit at such high velocity, thereby to prevent the accumulation of sediment in said coil and of any solid constituentsof the oil in said conduit.

17. In an oil burning system, the combination of a combustion chamber of silicon carbide, a refractory wall surrounding part of said silicon carbide combustion chamber and spaced therefrom, a burner nozzle for said combustion chamber and means for supply ing combustible mixture to said burner nozzle, the said means comprising a steam generator located outside the combustion chamber and inside the refractory wall whereby the generator is heated by conduction through and radiation from the silicon carbide partition, means for supplying water to said generator, an ejector with which the delivery end of said generator communicates, an oil conduit communicating with said ejector and a mixing duct between said ejector and said burner nozzle.

18. In an oil burning system, the combination of a combustion chamber of silicon carbide, a refractory wall surrounding part of said silicon carbide combustion chamber and spaced-therefrom, a burner nozzle arranged to deliver a combustible mixture to said chamber, a flash coil located outside the said combustion chamber and-inside the refractory wall whereby the flash coil is heated by conduction through and radiation from said silicon carbide wall, a mixing device with which the delivery end of said flash coil communicates, an oil conduit communicating with said mixing device, a conduit extending from said mixing device to said burner nozzle, a water supply conduit communicating with said coil and a valve in said water supply conduit, the cross-sectional areas of the said coil and of the conduit leading therefrom to the mixing device and of the conduit leading from the mixing device to the burner nozzle being restricted whereby the steam generated in the coil will be delivered at high velocity to the mixing device and the mixture from said device will pass through the second conduit to the burner nozzle at igh velocity thereby tending to prevent the accumulation of sediment in said coil and of solid constituents in said second conduit.

19. In an oil burning system, the combination of a combustion chamber, a burner for said chamber, the walls of said chamber being composed of a refractory of high thermal conductivity, an outer wall of poorly conducting refractory surrounding a portion of said conducting refractory and spaced therefrom, a steam generator between said highly conducting wall and said poorly conducting wall, an ejector to which the delivery end of said generator is connected, the steam passing at high velocity through a nozzle in said ejector, an oil conduit connected to said ejector, means for supplying oil continuously to a predetermined level below the said ejector, and a second conduit extending from the front or delivery end of said ejector to said burner, whereby the steam passing through the ejector draws with it a mixture of atomized oil which is supplied to said burner.

20. In an oil burning system the combination of a combustion chamber, a burner for said chamber, the walls of said chamber being composed of non-metallic refractory of high heat conductivity, an outer wall of poorly conducting refractory surrounding a portion of said conducting refractory and spaced therefrom, a steam generator between said highly conducting Wall and said poorly conducting Wall, an ejector to Which the delivery end of said generator is connected, an oil conduit communicating With said ejector, a nozzle in said ejector through Which the steam from said generator passes With high velocity, and means for supplying Water under pressure to said generator and means for varying the supply of Water to said generator, whereby the steam developed by transmission of heat through the conducting refractory produces a flow of atomized oil and highly heated steam into the burner.

21. A combustion chamber of silicon carbide adapted to be heated to incandescence by a combustible mixture fired therein, means for introducing such combustible mixture into said chamber an outer sleeve of high heat radiating material surrounding the combustion chamber to form an annular extension thereof and having a series of ducts through its lower end, and a fluid container surrounding said outer sleeve and positioned to be heated by radiant heat from said sleeve and by convection of combustion gases issuing from said ducts.

22. A combustion chamber of silicon car bide adapted to be heated to incandescence by a combustible mixture fired therein, means for introducing such combustible mixture into said chamber, an outer sleeve of high heat radiating material surrounding the combustion chamber to form an annular ex tension thereof and having a series of ducts through its lower end, a fluid container surrounding said sleeve and positioned to be heated by radiant heat from said sleeve as Well as by combustion gases issuing from said ducts and means for thermostatically controlling the supply of fuel to said cham-- ber in accordance With the pressure of the fluid container and the heat which passes through the combustion chamber.

In testimony whereof I hereunto aflix my signature.

JOHN W. CANNON. 

